The collection of content presentation, e.g., viewership, information is important to networks, advertisers, content delivery companies and many other entities for a variety of purposes and applications.
Traditionally, companies such as the Nielsen, relied on a group of viewers to keep a manual log of what they watched and when. The log information was collected and then compiled to generate program viewership information which might be reflected as TV viewership ratings and which also provided information about the number and age of viewers watching the programs.
The viewership information collected by ratings companies is often used for targeting advertisements, determining what TV shows are maintained or dropped by a TV network and for a wide variety of other applications.
While Television (TV) was and remains an important target for ratings services, as the distribution and presentation of a wide variety of programs has migrated to a wide variety of user devices in addition to TVs, there has been a growing need for methods and apparatus to track viewership information on a wide variety of different customer devices, e.g., handheld devices, personal computers, tablets, etc.
While content delivery network operators, e.g. cable companies, can track viewer information since the content delivery network is often able to track which content is being delivered to individual set top boxes or other customer premise devices, the information which is available to the content delivery network operator is normally prohibited to being distributed without express consent of the customer to which the content is delivered. Thus, even if a content delivery network has detailed content and/or viewing information they normally are prohibited from sharing such information with an outside ratings company.
While it might seem that a rating company could obtain authorization from the viewers who provide it with viewing information, this is often not a practical solution given that it would require the rating company to provide information about the viewers it is monitoring to generate the ratings statistics with the content delivery company, e.g., cable network operator. Ratings companies tend to try and keep the identify of the viewers who contribute to the ratings a carefully guarded secret to avoid a TV network or program producers targeting and/or somehow influencing the relatively limited set of viewers upon which the ratings are generated which are intended to be representative of the much larger viewing audience.
In order to overcome various problems, e.g., manual viewer tracking and reporting requirements, of the log approach to obtaining viewership information, audio watermarking techniques have been used to embed content identification information into programs which are broadcast by TV and Radio broadcasters and/or other content distributors. The audio watermarks, while not being detectable by the human ear, can be detected by a machine which processes an electronic version of an audio signal including the audio watermark.
In analog systems, the analog audio signal in electrical form may be monitored to detect the audio watermark. Simple signal pass through devices have been developed to be placed between the output of a set top box and the analog audio/video input of a television to monitor viewing of content that includes audio watermarks.
While the audio watermarking has served well in the context of analog systems, advances in digital communications technology have made it difficult to use with current content delivery networks. This is because the content is often encrypted while being communicated over the network and/or between secure devices. Thus, if a simple pass through monitoring device is used in many modern digital networks, it will simply observe encrypted digital data and be unable to identify the content being delivered based on the audio watermarks due to the encryption of the program content.
While the program content maybe decrypted in a secure playback device, the interface to the output device is often secure or integrated into the playback device eliminating the analog signal path into which an analog signal monitoring device may have previously been inserted.
In an attempt to overcome the problem presented by a lack of an analog audio signal interface into which a monitoring device can easily be inserted, the audio output of a playback device is monitored in some systems using a microphone and the audio signal captured by the microphone is then processed to detect watermark information.
While such an approach may be suitable for some applications, it has considerable disadvantages in that an acoustic signal needs to be generated and monitored. Furthermore, background noise and/or other acoustic problems may interfere with the reliable capture of generated audio signals and/or the recovery of program identification information.
In view of the above, it should be appreciated that there is a need for methods and apparatus which facilitate the collection of viewership information in an automated manner without relying on the capture of acoustic information, e.g., audio signals output by a speaker, and the processing of signals generated from the recovered acoustic signals.